Commit | Line | Data |
---|---|---|
59d5c8b1 AT |
1 | /* |
2 | * Marvell Berlin PWM driver | |
3 | * | |
4 | * Copyright (C) 2015 Marvell Technology Group Ltd. | |
5 | * | |
6 | * Author: Antoine Tenart <antoine.tenart@free-electrons.com> | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public | |
9 | * License version 2. This program is licensed "as is" without any | |
10 | * warranty of any kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | #include <linux/clk.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/pwm.h> | |
bbf0722c | 19 | #include <linux/slab.h> |
59d5c8b1 AT |
20 | |
21 | #define BERLIN_PWM_EN 0x0 | |
22 | #define BERLIN_PWM_ENABLE BIT(0) | |
23 | #define BERLIN_PWM_CONTROL 0x4 | |
24 | #define BERLIN_PWM_PRESCALE_MASK 0x7 | |
25 | #define BERLIN_PWM_PRESCALE_MAX 4096 | |
26 | #define BERLIN_PWM_INVERT_POLARITY BIT(3) | |
27 | #define BERLIN_PWM_DUTY 0x8 | |
28 | #define BERLIN_PWM_TCNT 0xc | |
29 | #define BERLIN_PWM_MAX_TCNT 65535 | |
30 | ||
bbf0722c JZ |
31 | struct berlin_pwm_channel { |
32 | u32 enable; | |
33 | u32 ctrl; | |
34 | u32 duty; | |
35 | u32 tcnt; | |
36 | }; | |
37 | ||
59d5c8b1 AT |
38 | struct berlin_pwm_chip { |
39 | struct pwm_chip chip; | |
40 | struct clk *clk; | |
41 | void __iomem *base; | |
42 | }; | |
43 | ||
44 | static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip) | |
45 | { | |
46 | return container_of(chip, struct berlin_pwm_chip, chip); | |
47 | } | |
48 | ||
49 | static const u32 prescaler_table[] = { | |
50 | 1, 4, 8, 16, 64, 256, 1024, 4096 | |
51 | }; | |
52 | ||
53 | static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip, | |
54 | unsigned int channel, unsigned long offset) | |
55 | { | |
56 | return readl_relaxed(chip->base + channel * 0x10 + offset); | |
57 | } | |
58 | ||
59 | static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip, | |
60 | unsigned int channel, u32 value, | |
61 | unsigned long offset) | |
62 | { | |
63 | writel_relaxed(value, chip->base + channel * 0x10 + offset); | |
64 | } | |
65 | ||
bbf0722c JZ |
66 | static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
67 | { | |
68 | struct berlin_pwm_channel *channel; | |
69 | ||
70 | channel = kzalloc(sizeof(*channel), GFP_KERNEL); | |
71 | if (!channel) | |
72 | return -ENOMEM; | |
73 | ||
74 | return pwm_set_chip_data(pwm, channel); | |
75 | } | |
76 | ||
77 | static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
78 | { | |
79 | struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm); | |
80 | ||
81 | pwm_set_chip_data(pwm, NULL); | |
82 | kfree(channel); | |
83 | } | |
84 | ||
59d5c8b1 AT |
85 | static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev, |
86 | int duty_ns, int period_ns) | |
87 | { | |
88 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
89 | unsigned int prescale; | |
90 | u32 value, duty, period; | |
91 | u64 cycles, tmp; | |
92 | ||
93 | cycles = clk_get_rate(pwm->clk); | |
94 | cycles *= period_ns; | |
95 | do_div(cycles, NSEC_PER_SEC); | |
96 | ||
97 | for (prescale = 0; prescale < ARRAY_SIZE(prescaler_table); prescale++) { | |
98 | tmp = cycles; | |
99 | do_div(tmp, prescaler_table[prescale]); | |
100 | ||
101 | if (tmp <= BERLIN_PWM_MAX_TCNT) | |
102 | break; | |
103 | } | |
104 | ||
105 | if (tmp > BERLIN_PWM_MAX_TCNT) | |
106 | return -ERANGE; | |
107 | ||
108 | period = tmp; | |
109 | cycles = tmp * duty_ns; | |
110 | do_div(cycles, period_ns); | |
111 | duty = cycles; | |
112 | ||
113 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); | |
114 | value &= ~BERLIN_PWM_PRESCALE_MASK; | |
115 | value |= prescale; | |
116 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL); | |
117 | ||
118 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY); | |
119 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT); | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | static int berlin_pwm_set_polarity(struct pwm_chip *chip, | |
125 | struct pwm_device *pwm_dev, | |
126 | enum pwm_polarity polarity) | |
127 | { | |
128 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
129 | u32 value; | |
130 | ||
131 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); | |
132 | ||
133 | if (polarity == PWM_POLARITY_NORMAL) | |
134 | value &= ~BERLIN_PWM_INVERT_POLARITY; | |
135 | else | |
136 | value |= BERLIN_PWM_INVERT_POLARITY; | |
137 | ||
138 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL); | |
139 | ||
140 | return 0; | |
141 | } | |
142 | ||
143 | static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev) | |
144 | { | |
145 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
146 | u32 value; | |
147 | ||
148 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); | |
149 | value |= BERLIN_PWM_ENABLE; | |
150 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN); | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | static void berlin_pwm_disable(struct pwm_chip *chip, | |
156 | struct pwm_device *pwm_dev) | |
157 | { | |
158 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
159 | u32 value; | |
160 | ||
161 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); | |
162 | value &= ~BERLIN_PWM_ENABLE; | |
163 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN); | |
164 | } | |
165 | ||
166 | static const struct pwm_ops berlin_pwm_ops = { | |
bbf0722c JZ |
167 | .request = berlin_pwm_request, |
168 | .free = berlin_pwm_free, | |
59d5c8b1 AT |
169 | .config = berlin_pwm_config, |
170 | .set_polarity = berlin_pwm_set_polarity, | |
171 | .enable = berlin_pwm_enable, | |
172 | .disable = berlin_pwm_disable, | |
173 | .owner = THIS_MODULE, | |
174 | }; | |
175 | ||
176 | static const struct of_device_id berlin_pwm_match[] = { | |
177 | { .compatible = "marvell,berlin-pwm" }, | |
178 | { }, | |
179 | }; | |
180 | MODULE_DEVICE_TABLE(of, berlin_pwm_match); | |
181 | ||
182 | static int berlin_pwm_probe(struct platform_device *pdev) | |
183 | { | |
184 | struct berlin_pwm_chip *pwm; | |
185 | struct resource *res; | |
186 | int ret; | |
187 | ||
188 | pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); | |
189 | if (!pwm) | |
190 | return -ENOMEM; | |
191 | ||
192 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
193 | pwm->base = devm_ioremap_resource(&pdev->dev, res); | |
194 | if (IS_ERR(pwm->base)) | |
195 | return PTR_ERR(pwm->base); | |
196 | ||
197 | pwm->clk = devm_clk_get(&pdev->dev, NULL); | |
198 | if (IS_ERR(pwm->clk)) | |
199 | return PTR_ERR(pwm->clk); | |
200 | ||
201 | ret = clk_prepare_enable(pwm->clk); | |
202 | if (ret) | |
203 | return ret; | |
204 | ||
205 | pwm->chip.dev = &pdev->dev; | |
206 | pwm->chip.ops = &berlin_pwm_ops; | |
207 | pwm->chip.base = -1; | |
208 | pwm->chip.npwm = 4; | |
59d5c8b1 AT |
209 | pwm->chip.of_xlate = of_pwm_xlate_with_flags; |
210 | pwm->chip.of_pwm_n_cells = 3; | |
211 | ||
212 | ret = pwmchip_add(&pwm->chip); | |
213 | if (ret < 0) { | |
214 | dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); | |
215 | clk_disable_unprepare(pwm->clk); | |
216 | return ret; | |
217 | } | |
218 | ||
219 | platform_set_drvdata(pdev, pwm); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | static int berlin_pwm_remove(struct platform_device *pdev) | |
225 | { | |
226 | struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev); | |
227 | int ret; | |
228 | ||
229 | ret = pwmchip_remove(&pwm->chip); | |
230 | clk_disable_unprepare(pwm->clk); | |
231 | ||
232 | return ret; | |
233 | } | |
234 | ||
bbf0722c JZ |
235 | #ifdef CONFIG_PM_SLEEP |
236 | static int berlin_pwm_suspend(struct device *dev) | |
237 | { | |
238 | struct berlin_pwm_chip *pwm = dev_get_drvdata(dev); | |
239 | unsigned int i; | |
240 | ||
241 | for (i = 0; i < pwm->chip.npwm; i++) { | |
242 | struct berlin_pwm_channel *channel; | |
243 | ||
244 | channel = pwm_get_chip_data(&pwm->chip.pwms[i]); | |
245 | if (!channel) | |
246 | continue; | |
247 | ||
248 | channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE); | |
249 | channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL); | |
250 | channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY); | |
251 | channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT); | |
252 | } | |
253 | ||
254 | clk_disable_unprepare(pwm->clk); | |
255 | ||
256 | return 0; | |
257 | } | |
258 | ||
259 | static int berlin_pwm_resume(struct device *dev) | |
260 | { | |
261 | struct berlin_pwm_chip *pwm = dev_get_drvdata(dev); | |
262 | unsigned int i; | |
263 | int ret; | |
264 | ||
265 | ret = clk_prepare_enable(pwm->clk); | |
266 | if (ret) | |
267 | return ret; | |
268 | ||
269 | for (i = 0; i < pwm->chip.npwm; i++) { | |
270 | struct berlin_pwm_channel *channel; | |
271 | ||
272 | channel = pwm_get_chip_data(&pwm->chip.pwms[i]); | |
273 | if (!channel) | |
274 | continue; | |
275 | ||
276 | berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL); | |
277 | berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY); | |
278 | berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT); | |
279 | berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE); | |
280 | } | |
281 | ||
282 | return 0; | |
283 | } | |
284 | #endif | |
285 | ||
286 | static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend, | |
287 | berlin_pwm_resume); | |
288 | ||
59d5c8b1 AT |
289 | static struct platform_driver berlin_pwm_driver = { |
290 | .probe = berlin_pwm_probe, | |
291 | .remove = berlin_pwm_remove, | |
292 | .driver = { | |
293 | .name = "berlin-pwm", | |
294 | .of_match_table = berlin_pwm_match, | |
bbf0722c | 295 | .pm = &berlin_pwm_pm_ops, |
59d5c8b1 AT |
296 | }, |
297 | }; | |
298 | module_platform_driver(berlin_pwm_driver); | |
299 | ||
300 | MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); | |
301 | MODULE_DESCRIPTION("Marvell Berlin PWM driver"); | |
302 | MODULE_LICENSE("GPL v2"); |